Automobile heater



H. J. DE MccoLLuM 2,191,175

Feb. zo, 1940.

AUTOMOBILE HEATER Filed April 6, 1938 Patented Feb. 20, 1940 UNITED STATES PATENT t(,)FFICE 2,191,175 AUTOMOBILE usaran Henry J. De N. McCollum, Evanston, lll.

Application April 6, 1938, Serial No. 200,312 i 2 Claims.

In the particular embodiment illustrated, the

l5 vacuum which is utilized for the purposes mentioned is that which is developed in the intake manifold of the engine. However, it is appreciated that, with this particular source, the degre of vacuum created ranges from zero to approxmately twenty-six inches of mercury, de-

pending upon the speed and the load to which the engine is subjected under operating conditions. Under such circumstances, if the degree of vacuum applied to the heat generator to draw the combustible mixture and hot gases through the heater were permitted to vary likewise, it is 4 apparent that the operation of the heater would be irregular and unsatisfactory. I

Consequently, it is one of the objects of the present invention to convert the widely varying degree of vacuum created in the intake manifold of an automobile engine into a substantially uniform working vacuum for operating al combustion heat generator of the class described.

Another object of the invention is to provide an improved means for causing a substantially uniform rate of flow of the gases of combustion through the heater.

Another object of the invention is to provide a compensator which provides a gradual compensating correction for variations in the degree of vacuum in the intake manifold of an internal combustion engine.

Another object of the invention is to provide in a heater of the class described, a compensator therefor, which is simple in construction and operation, effective in use and inexpensive to manufacture and operate.

Another object of the invention is to provide a compensator for an internal combustion heater for regulating the pressure differential employed in the operation of the heater, which is fully adjustable throughout all vacuum differentials and easily disassembled for repair and maintenance.

These being among the objects of the invention, other and further objects will become apparent from the drawing herein, the description relating thereto, and theappended claims.

Referring now to the embodiment of the invention illustrated, partly in section, in the single e view of the-accompanying drawing, the heater construction ylil, `which is more particularly described in said co-pending application, comprises generally. a carbureting device l2 supplied with gasoline preferably from the float bowl lli of the lil usual engine carburetor. Suitable means is provided to control the ow of gasoline to the heater il) and the amount of air mixed therewith in order to supply to the heater several combustible mixtures of different degrees of richness to take lib `care o f the various heater requirements encountered under starting and running conditions.

The combustible mixture supplied by the carbureting device is fed into the combustion chamber I6 through a tube iB and a perforated bafe Q0 plate 20 by means of which preheat and turbulence are effected to `thoroughly vaporize the mixture entering the combustion chamber. The mixture is ignited' by an electrical heating element 22 located in a recess 2d in the side of the 25 chamber, and, in event the flame ever becomes extinguished, the mixture is reignited by a refractory ceramic plug 2B at the outlet of the combustion chamber which acquires a sumclently high temperature for such purpose by being di- 3u rectly exposed to the llame during the normal operation of the heater.'

From the combustion chamber it the hot gases pass through a radiator 2B comprising a circuitous tube. all 'to which heat radiating fins 32 a5 are thermally connected. Over these iins air is circulated in a `manner whereby heat is transierred from the hot gases to the passenger compartment of the automobile for the comfort of the passengers. @0

The ow of gases through the heater i il is controlled 1n two Ways: one. by the valve 36 which starts and stops the iiow, and the other by a compensator 40 l interposed between the heater it and the intake manifold for regulating and rendering @5 uniform the degree of vacuum to which the heater is subjected.

In the particular embodiment of the compensator illustrated by enlargement in the accompanying drawing, a butterfly valve t3 is mounted 50 within a pipe M connecting the heater l0 with the intake manifold to compensate for variations in intake manifold vacuum.

The stem 46 of the butterfly valve has an arm 4s secured thereto, the free' end of the arm being connected by link 50 to a piston 52 which is freely reciprocal in the cylinder 54. The cylinder is in communication with the pipe 44 through a relatively small port 56 and the piston is normally held in the position in which it is shown by a compression coil spring 58 whenever the vacuum differential ranges from zero to the degree necessary for the best operation of the heater. The lower end of the spring 58 rests upon a swivel retainer 60 which is carried by an adjusting screw 62 so that the effectiveness of the butteriiy valve 42 may be varied at will according to the diierent requirements which a user may seek to impose upon a heater such 'as that illustrated and described herein.

When the intake manifold vacuum is of a normal value, the spring will offer suiliclent resistance to the downward movement of `the piston to hold the butterfly valve in its completely open position as shown. `When, however, the intake manifold exceeds that necessary for the best operation of the heater, the decrease in the pressure will be transmitted through the port 56 to the cylinder 54 beneath the piston 52 and the atmospheric pressure upon the top of the piston will force the piston downwardly against the force of the spring 5B, thus partially closing the buttery valve 42 in direct relationship with the degree of pressure differential existing upon both sides of the piston 52.

Partial closure of the valve 42, will ofcourse result in decreasing the rate of ow of the gases ofv combustion from the heater and thereby compensate for such changes in the intake manifold vacuum as from time to time will be experienced in engine performance. The Aport 56 is made sufciently small that the opening and closing of the butterffy valve will be relatively gradual and will be free from fluttering.

In this way, a compensator which is simple in form and easily constructed, operated and ymain-- tained, is provided for an internal combustion heater which converts the widely varying degree of vacuum to which the heater might otherwise be directly subjected with a substantially uniform working vacuum for causing a substantially uniform rate of ilow of the gases of combustion through the heater under gradually compensating corrections within the objects expressed and implied herein.

Consequently, although a single embodiment of the invention has been shown and described' herein, it will be apparent to those skilled in the art that various and further uses, modications and changes may be made without` departing from the spirit and substance of the invention, the

scope of which is commensurate to the appended claims.

What is claimed is:`

1. In an automobile heater of the class described which utilizes vacuum developed in the intake manifold of the automobile engine, the

combination comprising, means providing a combustion chamber, means for feeding fuel ,to the variations in pressure in the intake manifold, the

last mentioned means comprising a valve in said conduit, a casing providing a cylinder open at one end and having an opening therein near the other end, means connecting the said opening in the casing to the conduit intermediate the said valve and the combustion chamber, a piston slidable in the cylinder and disposed between the open end thereof and said opening in the casing so as to be exposed to atmospheric pressure on one side and to pressure within a portion of the conduit on the other side, a spring biasing the piston toward the open end of the casing, and a link connecting the piston to the Valve in the conduit so that the valve is moved responsive to movements of the piston.

2. In an automobile heater of the class described which utilizes vacuum developed in the intake manifold of the automobile engine, the combination comprising, means providing a combustion chamber, means for feeding fuel to the combustion chamber, a conduit connecting the combustion chamber to the intake manifold to effect a reduction of pressure within the combustion chamber, a valve for shutting oi the conduit, and means for compensating for variations in pressure in the intake manifold, the last mentioned means comprising avalve in said conduit, a casing providing a cylinder open at one end and having an opening therein near the other end, means connecting the said opening in the casing to the conduit intermediate the said valve and the combustion chamber, a piston slidable in the cylinder and disposed 'between the openl end thereof and said opening in the casing so as to be exposed to atmospheric pressure on one side-and to pressure within a portion of the conduit on the other side, a spring biasing the piston toward the open end of the casing, and a link connecting the piston to the valve in the conduit so that the valve is moved responsiveto movements of the pistoni HENRY J. DE N. MCCOLLUM. 

